1. Field of the Invention
This invention relates generally to Voice Over Internet (VoIP) protocols and architectures. More particularly, it relates to conferencing services using VoIP.
2. Background of the Related Art
Voice-Over-Internet Protocol (VOIP) is a technology that emulates a phone call, but instead of using a circuit based system such as the telephone network, utilizes packetized data transmission techniques most notably implemented in the Internet.
The use of VoIP technology is growing quickly. Given VoIP technology, there are at least three VoIP scenarios:                1. A VoIP UA that is physically connected to a static data cable at a “home” address. For instance, an Analog Telephone Adapter (ATA) that is connected to the “home” data cable and uses traditional telephone devices.        2. A VoIP UA that is physically connected to a data cable at a location different than its “home” address. For instance, a laptop computer device utilized away from home as a VoIP software telephone would be a VoIP ‘visitor’ device as described by this scenario.        3. A VoIP UA that is wireleless, physically disconnected from any data cable.        
In this situation, the VoIP UA connects to the VoIP service provider via either a wide-are wireless technology (e.g., cellular, PCS, WiMAX) or via a local-area wireless technology (e.g., Wireless Fidelity (WiFi), UWB, etc.) using a laptop computer or handheld device.
VoIP phone calls are routed to a VoIP voice gateway, from which they are passed on to their destination. A VoIP voice gateway or soft switch is a programmable network switch that can process the signaling for all types of packet protocols. Also known as a ‘media gateway controller,’ ‘call agent,’ or ‘call server,’ such devices are used by carriers that support converged communications services by integrating SS7 telephone signaling with packet networks. Softswitches can support, e.g., IP, DSL, ATM and frame relay.
VoIP telephone technology is quickly replacing conventional switched telephone technology. A location of a given VoIP device may be provisioned to be at a given geographic location, or queried from a home location register (HLR) in a mobile system.
With given VoIP technologies, a VoIP user must know the specific phone number of an individual, business, or other entity that they wish to call. There is no conventional technique for allowing a conference call between two or more VoIP users. In the Internet venue, users can find each other using a “chat room”, but the burden nevertheless remains on the user to search for, identify, and use a specific phone number or Universal Resource Identifier (URI) information to reach specific entities. This creates inefficiency and lack of flexibility with respect to the desire to establish a conference call, preventing VoIP users from managing their own communication needs and preferences. Generally, voice communication using VoIP technologies is limited to only point-to-point direct links between familiar or previously identified parties.
There is a need for an architecture and methodology that simplifies the complexity of conferencing VoIP calls.